CUT 80/100/120 Pilot Arc

Transcription

1 USER MANUAL AND INFORMATION CUT 80/100/120 Pilot Arc INVERTER PLASMA CUTTER Using Trafimet A-141 Cutting Torch with Euro Connector

2 Thank you for purchasing a PlasmaPart Plasma Cutter We have included this information pack as a reference document for all users; it is intended to provide information relating to all areas of plasma cutting from health and safety to operational tips. We strongly advise you to keep this document with the machine. It is important you familiarise yourself with the information within this guide, both for your safety and ease of operation of the unit. Important Health and Safety Information This unit in common with all plasma cutters uses a combination of very high voltage, current and power to generate the high temperatures required to cut metals. Note: This is a Pilot Arc Machine and the Torch will light as soon as the trigger is pressed irrespective of material contact. A plasma cutter can cause injury or death if used incorrectly. There are several hazards associated with plasma cutting: Heat The plasma beam created at the torch tip exits around 25,000 C this presents a serious hazard if the plasma beam were to come in contact with you. as The molten metal produced in the process can also cause damage or injury to you if your feet or other parts of your body are not adequately protected. Plasma cutting should not be carried out within close proximity to any flammable substances or materials. Electricity Unlike conventional welding equipment the voltage present at the torch tip when energised can be very high presenting a risk of electrical shock or electrocution if care is not taken in use. The torch tip could, under fault conditions be at 350V d.c. when the trigger is pressed. It will also have a spark voltage in excess of 5000V under normal operating conditions as the machine try s to establish an arc. Unlike normal mains electricity a.c. supplies this d.c. supply will cause muscle contraction rather than spasm and may cause the hand to lock onto the supply rather than being thrown off - if you come in contact with it. Great care must be taken to ensure you do not come in contact with the tip or any contacts on the machine whilst it is on. This machine must be earthed. The high power requirements of this machine are common with all plasma cutters. 2

3 The CUT 60/80/100/120 series of machines should only be connected to a 32A 4 wire 3 phase ( V) supply and earth. If in doubt please contact a qualified electrician for advice. The tip should always be in contact with the work-piece before cutting is started and whilst cutting is carried out - this ensures the cleanest cut, minimises the risk of molten metal being thrown toward the operator and minimises power usage of the machine. Compressed air The unit requires a compressed air supply to operate. All pipe work should be kept in good condition and checked regularly for damage. Air at high pressure can penetrate the skin if directed onto it at close range - this can cause blood clotting and even death. Even at a low pressures compressed air can be dangerous (even fatal) if it is introduced into any orifices of the body. Visible and Ultra Violet Light The visible light generated by the arc process is not as intense as some welding operations but can cause serious eye damage if the eyes are not protected during the cutting operation. SHADE 5 goggles are considered adequate for most purposes and are supplied with the unit. If the eyes become sore or irritated it would be advisable to seek professional help and increase the shading level. The safety glasses provided are also recommended to help protect eyes from flying debris. As with most arc welding processes skin should be protected from exposure to the ultra violet light emitted during the cutting process. Airborne Debris Due to the way a plasma cutter operates airborne debris is generated and blown into the air by the compressed air, it is strongly advised that the unit is operated in a well-ventilated environment. It is also recommended that a mask of appropriate grade is worn to prevent ingress of fine debris into the lungs. Electromagnetic Radiation and Strong Magnetic Fields In common with all welding and cutting machines the CUT 45 emits strong magnetic and electromagnetic fields when in close proximity to the machine. Persons with pacemakers or other artificial life support systems should remain at least 2 metres away from working machines without the advice from a doctor of their system manufacturer s recommendation. 3

4 Specification Supply Voltage Supply Frequency Power requirement (at 120A) Rated input current (at 120A) No-load voltage Output current range Output voltage range Duty 120 Amps Output 3-ph AC V 50~60 Hz 15 KVA (Max) 32 A (Max) per phase 350 V A V 40 Deg C ambient Efficiency 88% Cut Width 1.0 mm (Nozzle type dictates) Arc striking model HF Start Pilot Arc Cos φ (η) 0.93 Air pressure psi Instruction Notes 1. Operating environment 1.1 The CUT 60/80/100/120 machines can be operated in harsh weather conditions at temperatures of between -10 and +40 Degrees Centigrade and a Relative Humidity of 80%. 1.2 Do not place the machine in direct sunlight or operate it in the rain. 1.3 Keep the machine dry and avoid any contact with water. 1.4 Do not use any machine in a dusty atmosphere or one containing a corrosive or explosive gas. 1.5 If the machine will not be used for a long period of time it should be returned to its original packing box and stored in a dry environment. 1.6 The internal fans cool the high power electronics and the entry and exit ventilators must not be obstructed. Ensure there is sufficient space in front and behind the machine for the forced air to circulate. 1.7 Ensure the power cable is connected to a supply which has the correct voltage and current rating. The machines have built in electronic control to adjust for different mains voltage over a limited range. There is a label on the back of the machine indicating the machine setting. Units supplied to the UK will be set for V a.c. which is suitable for three phase, three wire supplies and an earth connection. 1.8 Always stand the machine on a level surface to prevent the unit overturning. 4

5 2. OPERATING SAFETY 2.1 Ensure the working area is adequately ventilated and clear of all flammable materials. 2.2 Avoid physical contact with the cutting tip when the power is on. The tip could be at a potential of 350Vdc when the torch switch is activated, this reduces during the cutting process but both voltages can cause serious electric shock. 2.3 Always turn the machine power off and remove the plug before servicing or changing the cutting head components. 2.4 When using the machine on site or outside ensure the grounding terminal on the back of the machine is connected to a safety earth. This will prevent any leakage current from the cutting circuit causing an electric shock to the operator. A cable with a cross sectional area of 6mm 2 is suitable for this purpose. Neither the torch lead or earth clamp are directly connected to the mains earth inside the unit although the unit case is itself earthed to the mains cable earth wire. 2.5 Do not cut containers or pipes which have held or contain gaseous or liquid fuels or combustible substances. 2.6 Do not cut any containers or pipes which may be under pressure. 2.7 Always wear eye protection. This is to protect your eyes from both the arc and also sparks which are produced during the cutting operation. 3. Setting up the machine 3.1 Check the cutting torch head is assembled correctly. See Appendix 4. The Euro connector connection provides both the compressed air and cutting current to the torch. A lead with a large crocodile clip is provided in the box for material current return. 3.2 Connect the mains cable to a suitable high current supply. The OC light will come on and the unit will lock out if the mains supply at the unit drops below the lower 15% voltage limit when the cut switch is operated. There is an internal monitoring function inside the unit to prevent damage to the electronic components. The Key Lock on the front of the machine must be turned on for the machine to operate. 3.3 Connect the air regulator to the compressor with the compressor set to its maximum pressure output. The Torches consumes approximately 230 Litres / minute ( 9 cu ft.) of air per minute at 100PSI PSI (100psi = 6.7bar, 0.67MPa). Set up the air pressure for the machine. To do this set the current control to 20A and turn the mains power switch on. With the torch pointing away from you press and hold down the control switch on the torch. Take extreme care as the torch will light when the switch is pressed. Important - do not hold the cutting switch down in free air for more than 10 seconds. The air control solenoid will operate and air will flow through the. Nozzle. Adjust the air regulator for a gauge reading of 100psi (0.66 MPa, 0.66Bar) with the air flowing through the torch. Release the switch. This set up will ensure that there is an air pressure of 100 psi behind the cutting tip which is a good starting point for use with the consumables and torch supplied with the unit - this can be varied according to the material being cut, with thicker cuts and different materials requiring more or less air flow. 5

6 Do not keep the torch switch depressed for long periods without contacting the metal. The circuit is only designed for short duration operation to initiate the arc. Switch the machine off. 3.4 Connect the current return electrode to the material being cut. It may be necessary to remove a small part of the surface corrosion if black steel or rusty Iron is to be cut. This will ensure the current return electrode is making good contact with the base metal. 3.5 Observe the Duty Cycle, which is 60% at full output. If a long thick cut has been made for say 6 minutes, allow the machine to rest for 4 minutes before making a further cut. This will give the electronics time to cool. If machine gets too hot a monitoring circuit will automatically stop the machine working until the unit has reached a safe level to continue. This is indicated by the OC light illuminating on the front panel and the arc will not strike. Leave the machine switched on to allow the fan to cool the electronics. It is necessary to turn the machine power switch off and on again to reset the monitoring circuit. 3.6 The cutting current is maintained at the value set by the control on the front panel. The machines cannot be overloaded; the machine has a built in electronic control circuit which ensures the arc current flowing remains at the value set by the control knob. 3.7 The machine is now ready to cut. 4. Cutting Operation To begin the cut place the nozzle or guide in direct contact with the material and pull the trigger, the plasma will start and cutting can commence. Note: The material can be rusty, painted or badly corroded, there is no need for a clean surface as the pilot arc will burn through to the base material. Keep the nozzle in contact with the material during the cutting operation. The air must have stopped flowing from the nozzle before the torch will light. Wait for the air flow to stop before operating the torch switch to start the cutting operation. 4.1 The cutting current is dependent on three parameters; material thickness, speed of cutting. (Travel speed of the torch) and standoff (distance between the cutting tip and parent material being cut) in practice it has been found that it is easier to set a current appropriate to the material thickness then adjust the speed of cutting to achieve the desired result if the tip standoff is kept constant. When the correct combination is achieved the sparks from below the material being cut will lag slightly behind the cutting tip. Move too quickly and the sparks tend to come from above the cut and the plasma will not penetrate all the way through the material. Moving too slowly will result in a wider cut, heat distortion and a build-up of dross (slag) on the underside of the material. Eventually the arc will be lost. It is good practice to try a few cuts on scrap material where you can establish a speed of cutting that is comfortable to achieve. The interdependence of the three parameters is explained in more detail below. 4.2 The two terms that are commonly used to describe the quality of the cut in Plasma cutting are Kerf (cut width) and Dross (slag). 4.3 Kerf is the width of material (perpendicular to the torch and cut axis) removed during the plasma cutting process. Kerf is affected by two variables. 6

7 Cutting Speed The faster travel speeds will result in a narrower kerf. The kerf will continue to narrow until loss of penetration occurs. Slower travel speeds will result in a wider kerf until loss of arc occurs. Cutting Amperage Increasing cutting amperage will result in a wider kerf. Continuing to increase current will widen kerf until the nozzle is destroyed. Lowering amperage will result in a narrower kerf and a more positive cut angle until penetration is lost. Standoff is the distance maintained between the torch tip plasma exit hole and workpiece. The tips supplied with your torch have a built in standoff between the plasma exit and work piece and have been designed to remain in contact with the material being cut. If the standoff is increased during cutting the machines have an arc voltage feedback system which will increase the arc voltage as the standoff distance increases and widen the kerf. Continuing to increase standoff will eventually lead to loss of cut. The unit will electronically maintain the constant set current if the standoff distance is changed. 4.4 Dross (slag) is the excess material that spatters and builds up on the underside of the material as you cut. Dross occurs when the operating procedure and technique is less than optimal. It will require practice and experience to obtain cuts without dross. Although less than optimal cuts will contain dross, it is relatively easy to remove by breaking it off using pliers or chipping off with a chisel. A combination of factors contributes to the build-up of dross. These include material type, material thickness, amperage used for the cut, speed of the torch across the work-piece, condition of the torch tip, air pressure, etc. Do not use more output current than is necessary and adjust speed of cut to minimise dross build-up on underside of cut. Try carrying out further experiments adjusting current and speed to minimize dross and obtain a satisfactory result. When cutting aluminium a lower air flow rate is used to obtain a cleaner cut. 4.5 Cutting tip angle. It is important to keep the cutting tip near to vertical in the direction of travel and also at right angles to the direction of the cut. Basically the plasma will cut in the direction the tip is pointed. This can be used to advantage if a weld preparation is needed on the material being cut. When reaching the end of the cut tip the torch slightly away from the end of the material to sever the final bridge. The same technique in the opposite direction can also be useful when starting the cut. 5. Maintenance Please note that not all A-141 Plasma Torch consumables available are of the same design and dimensions. The torch, torch cable and spares provided with this unit and available from us have all been selected, inspected and tested to ensure they meet our required specification. Some cutting tips available from other suppliers will require a standoff to be maintained in use and other consumable components may require a higher air pressure to function correctly; some parts available will not function correctly at all. 5.1 Before use Check the power connection and air supply hose for damage. Repair or replace any 7

8 damaged items before use. Check the condition of the shroud, cutting tip, electrode and swirl ring. Replace as necessary. Check the torch is assembled correctly for the cutting current to be used. Check the ground clamp connection and cutting torch cables for damage. Repair or replace as necessary. Ensure these are tight to their respective connections on the unit. 5.2 During use Regularly check the cutting tip and shroud for a build-up of dross (slag) from the cutting process. Brush off any build up with the wire brush provided. Avoid enlarging the hole in the tip through which the Plasma exits. Always switch off the machine before touching the cutting tip or dismantling the torch. 5.3 After use Disconnect earth lead and torch from the unit Dismantle the torch and clean the ceramic cup, electrode, swirl ring and cutting tip. The electrode and cutting tip can also be cleaned with 120 grit wet and dry paper. Re-assemble the torch and store items in a safe place. The shroud is easily damaged, if it comes into sharp contact with a hard surface. This information should be considered important and you must understand it before using the CUT 60/80/100/ plasma cutters for your own and others safety. If there is something you don t understand please contact PlasmaPart Ltd. for clarification. We are here to help! 8

9 Declaration of Conformity The undersigned Company - PlasmaPart Ltd. Unit 7, Waldron Court, Prince William Road, Loughborough, Leicestershire. LE11 5GD. Declares that the product identified and described on this page has been tested by their supplier and complies with standard EN in accordance with the requirements of directive EEC 73/23 Low Voltage Directive Certificate valid until Portable Appliance Testing This equipment is tested in accordance with the IEE Code of Practice - 3 rd Edition - Inspection and Testing of Electrical Equipment - by a person holding recoginised qualifications using calibrated test equipment as part of PlasmaPart Ltd. Pre- Despatch QA procedures. 9

10 Troubleshooting - Appendix 1 PROBLEM POSSIBLE CAUSE SOLUTION Plasma arc will not start Unit not powered up Work clamp connection Air supply is low pressure OC Light on front panel of unit comes on Check mains supply and on/off switch is on Check ground clamp has a good connection to the material being cut, clean surface of material if it is dirty or corroded Check air is flowing from the torch tip with cut switch pressed. Check the compressor is maintaining 75psi at the gauge while cutting is in progress. Check the regulator fittings have been assembled properly using PTFE tape. Check the cutting tip is not blocked by dross Switch machine off and wait about 2-3 minutes, Switch machine back on. This can occur if the unit duty cycle is exceeded (overheating) Use 32A cable for power lead extensions. Air Supply / Torch Technical problem with the unit Try operating the cutter at 20A set current, if this is OK then there is a problem with the stability of the mains supply to the unit. Use a different power source or thicker mains cable to connect to the unit mains lead. The unit will typically draw 32A per phase from the mains supply when cutting at 120A. The torch will not start if air is coming out of the nozzle. Wait for the air flow to stop before operating the switch. Check the torch has been assembled correctly. See Appendix 4 for details. The swirl ring is easily missed out from the assembly. enquiries@plasmapart.com

11 Troubleshooting - Appendix 2 PROBLEM POSSIBLE CAUSE SOLUTION Plasma arc stops while cutting Sparks are shooting upward not downward through the material Hand too tense, inadvertently releasing the cut switch Cutting speed too slow Torch moved too far away from material Compressor unable to keep up with air demand Technical problem with the unit Plasma arc not piercing material Hold the torch lightly against the material being cut, don't push down. Try and relax the hand. Check air pressure gauge reading when cut stops. Check air pressure is 100psi Check torch lead connections at unit and torch are tight. Check torch hose is undamaged. Check torch 'O' ring is intact and undamaged Check shroud for fractures. Check compressor, give the compressor time to recover if making long cuts when using a smaller compressor. Check the regulator fittings have been assembled properly using PTFE tape. enquiries@plasmapart.com Torch travel speed too fast Check grounding clamp is making a good connection to the material being cut and is tightly connected at the unit. Clean a patch of material for clamp if rusty Increase current

12 Troubleshooting Appendix 3 PROBLEM POSSIBLE CAUSE SOLUTION Insufficient cut penetration Cutting speed too fast Insufficient current Beginning and end of cut not severed Dross build up on parts of the cut Consumables wear quickly Worn or damaged torch electrode or tip. Torch positioning Cutting speed too slow or not consistent Material getting too hot Current too high Air pressure too low Torch position Poor maintenance Tilt the top of the torch towards the direction of travel as you start the cut. Tilt it away from the direction of travel when you are finishing the cut. Try keeping a constant and steady cut speed for a set current Allow material to cool before continuing the cut Re-check gauge pressure is at 100psi Tilt the top of the torch toward the direction of travel when cutting the thickest material. This will reduce the blow back into the torch tip. Frequently clean the dross off the cutting tip using the wire brush provided. Cut is not vertical Torch position The torch cuts in the direction that the plasma arc is pointed. Keep the torch vertical for a vertical cut. The tip can be angled to produce a weld prep if this is required on the material being cut. Torch will not switch off when cut switch released Cut switch problem Electronic Fault in unit Check the cut switch contacts at the machine end of cable for correct on/off circuit enquiries@plasmapart.com

13 Appendix 4 A-141 Trafimet Torch Assembly Note the position of the swirl ring, it fits tightly to the nozzle and can be easily missed or lost. 13

14 SAFE SYSTEM OF WORK PLASMA CUTTING (Please note: This is a generalised SSW and it should adapted to suit your own operations and systems) RISKS There are significant Health and Safety risks that can occur from plasma cutting processes, these are detailed if the Risk Assessment and comprise the following: Intense ultra violet and infrared radiation Fumes from the cutting process Heat Electric shock Electromagnetic Radiation Ignition of combustible material Unauthorised use Danger from pipes, vessels and cables SAFE SYSTEM OF WORK INTENSE ULTRA VIOLET AND INFRA RED RAYS The operator should always wear suitable eye protection and ensure other observers eyes are also protected. Post signs to warn other people of the visual danger from the operation or work in a restricted area. FUMES Only use the equipment in a well-ventilated area. HEAT Use appropriate gloves, clothing and footwear during all cutting processes. Point the torch into a safe area before pulling the trigger. The Pilot Arc will start instantaneously and cause severe burns if it made contact with exposed or covered skin. ELECTRIC SHOCK Always turn the machine power off before servicing the cutting torch. Check the mains plug and cable for cuts or burns before the power is turned on. Report any defects before using the machine 14

15 Ensure colleagues are aware of how to deal with a person suffering from electric shock. ELECTROMAGNETIC RADIATION Any person fitted with a heart pacemaker must not be permitted to be closer than 2m of any operational electrical cutting equipment. IGNITION OF COMBUSTIBLE MATERIAL Combustible materials are not to be used, stored or allowed to accumulate in the welding/cutting area. Sparks and molten metal from the cutting process can travel a long way. UNAUTHORISED USE (CUT 80/100/120 only) Always switch the machine OFF and turn off and remove the safety lock key before leaving the machine unattended. The torch will not light with the key switch set off. DANGER FROM PIPES, VESSELS AND CABLES Ensure any pipework to be cut is free from chemical contamination. Some chemical elements could explode or create noxious fumes when heated to plasma cutting temperatures. Ensure any vessel or cylinder to be cut does not contain any flammable gas, fuel or pressure before cutting. Avoid working near to cables which may be live. Do not cut cable which has insulation, burning insulation could create noxious fumes. Keep the machine power cables and torch power connection away from the cutting area. 15

16 RISK EVALUATION AND PRECAUTIONS FOR WELDING AND CUTTING OPERATIONS (Please note: This is a generalised Risk Assessment and it should adapted to suit your own operations and systems) The potential risks from welding or cutting operations are identified as follows: 1. Intense ultra violet radiation and Infrared rays 2. Fumes 3. Heat 4. Electric Shock 5. Electromagnetic radiation / Strong magnetic fields 6. Ignition of combustible material 7. Compressed Air The following safety precautions have been taken by the Company to overcome or mitigate the risks involved with electrical welding or cutting operations: INTENSE ULTRA VIOLET RADIATION AND INFRA RED RAYS To protect from intense visible and ultraviolet light safety glasses or a helmet will be provided with an appropriate filter lens to reduce the light intensity and protect the face and eyes from the heat generated in the processes. FUMES A downdraught ventilation and filtration cabinet should be used to remove sparks and welding fumes and gasses from the immediate vicinity of the operator. HEAT Appropriate clothing and gloves are provided and will be worn during all welding and cutting processes. ELECTRIC SHOCK Whilst the effect of a shock from the high voltage is unpleasant it is unlikely to be fatal. The power supply to the machine should be switched off before adjustment or servicing is carried out on the torch to prevent accidental contact with the spark or cutting power source. Most welding plant is classified as Class 1 Moveable Equipment and in an industrial environment there is a legal requirement that user checks are made each time before the equipment is used. ELECTROMAGNETIC RADIATION Regulations state that any person fitted with a heart pacemaker or other life support device will not permitted to be closer than 2 metres of any operational welding or cutting equipment. A warning sign to this effect is included on entry doors to the welding/cutting area. IGNITION OF COMBUSTIBLE MATERIAL Combustible materials are not to be used, stored or allowed to accumulate in the welding/cutting area. 16

17 USE OF COMPRESSED AIR The unit requires a compressed air supply to operate. All pipe work should be kept in good condition and checked regularly for damage. Air at high pressure can penetrate the skin if directed onto it at close range - this can cause blood clotting and even death. Even at a low pressures compressed air can be dangerous (even fatal) if it is introduced into any orifices of the body. 17